Some connectors are mounted on a circuit board and then used to establish an electrical connection between a flat cable and the circuit board. These connectors are configured to receive an inserted end portion of the flat cable. These connectors have a retainer to keep the flat cable from becoming detached. In Patent Document 1, a notch is formed in both the left and the right edges of a flat cable (FPC 10 in Patent Document 1), and the retainer (contact 7) has a front upper beam (contact portion 75) extending forward from the base portion (hinge portion 74) and a rear upper beam (lever portion 76) extending rearward from the base portion. An engaging portion (lock portion 75a) is formed in the leading end of the front upper beam to engage the notches in the flat cable. The cam portion of an actuator (contact force applying member 9) is arranged on the lower side of the rear upper beam. After a flat cable has been inserted into the connector, the actuator is tilted to the rear. Then, the rear upper beam is pushed upward by the cam portion of the actuator and the front upper beam is tilted downward. As a result, the engaging portion (lock portion 75a) of the front upper beam engages the notches in the flat cable. This keeps the flat cable and the connector from becoming detached.
Patent Document 1: Laid-Open Patent Publication No. 2005-78908